High temperature fractional quantum Hall states

TL;DR

This paper proposes a theoretical framework where geometric frustration, ferromagnetism, and spin-orbit coupling create nearly flat bands with non-zero Chern numbers, enabling fractional quantum Hall states potentially at room temperature.

Contribution

It introduces a novel combination of physical effects to realize high-temperature fractional quantum Hall states, guiding future material exploration.

Findings

Nearly flat bands with large bandgap and non-zero Chern number are achievable.

Partial filling of these bands can produce fractional quantum Hall states at high temperatures.

Material candidates remain to be identified, but the theoretical pathway is established.

Abstract

We show that a suitable combination of geometric frustration, ferromagnetism and spin-orbit interactions can give rise to nearly flat bands with a large bandgap and non-zero Chern number. Partial filling of the flat band can give rise to fractional quantum Hall states at high temperatures (maybe even room temperature). While the identification of material candidates with suitable parameters remains open, our work indicates intriguing directions for exploration and synthesis.